Workers in the item-transport (e.g., document-transport arts are aware of the need for better means to feed items from a pack and to separate items behind the foremost item in the pack (i.e. "following items").
For instance, workers recognize how documents feeders co-act with document separators to feed documents singly, in order, from a pack (input hopper). It is assumed that a document feeder is a device for separating one document from a stack (pack) thereof and feeding it to another device, such as a document transport. This invention contemplates using a separator belt (or roll) in conjunction with the document feed wheel and controllably varying the speeds of each (belt/wheel) to produce optimal document advancement at a variety of feed rates. Furthermore, the speed of such a separator belt (or roll) is taught as being varied without varying the feed wheel speed, to thus optimize feeder performance for a variety of document types and/or document conditions.
Purpose
Our purpose is to minimize document "feed errors", and feeder jams, and to maximize throughput, doing so with a document feeder (fixed or variable speed). Document "feed errors" can be: feeding two or more documents at once, feeding documents overlapped, or feeding documents too close together.
Salient Novel Features
The speed of such a separator belt can be varied to maintain optimal document feeder performance when the speed of the associated feedwheel is changed. Also, for document feeders with fixed feedwheel speed, separator belt speed can be changed to optimize feeder performance for a variety of document conditions and document types. Fundamentally, the separator speed is adjusted to be more closely related to the velocity of document leading edges in the "wedge" that is formed just upstream of the feedwheel/separator nip. Depending upon document conditions, this speed may be varied above or below a nominal value to optimize feeding reliability. Since some document processing equipment may require various feed rates from the feeder because of various downstream processing options, separator speed can be varied in accordance with feedwheel speed and to maintain a reliable, constant document feed.
Advantages
More conventional separator belts (or rolls) run at a constant speed, primarily so as to distribute wear, or to present fresh, new belt material to the feedwheel/separator nip and so maximize separation friction. Also, some separator belts (or rolls) may be stationary, requiring frequent replacement because of wear or contamination from documents.
A system according to this invention can thus be set up to adapt a separator to adjust to changes in feed rate, documents, etc. Also, various electrical utilization circuits can control the feeder and separator together, and adjust for document/machine conditions.
This invention takes advantage of elements that already exist and adapts them to shifting conditions in document-feed. Worker will realize that this invention can be used for document sorters, mail sorter, copiers, page feeders, punch card pickers and transports, envelope stuffing machines, money feeders, fax machines and automatic teller machines.
Thus, an object hereof is to alleviate at least some of the foregoing problems and effect at least some of the foregoing advantages and results. A related object is to do so for an item feeder/separator arrangement used to advance documents or the like from a pack.